Mitigating the formation of monochloropropanediol diesters in vegetable oils by removing their residual sediments

Influence of the Degumming Process Parameters on the Formation of Glyceryl Esters and 3-MCPDE in Refined Palm Oil: Optimization and Palm Oil Quality Analyses

The presence of glyceryl esters (GE) and 3-monochloropropane-1,2-diol esters (3-MCPDE) in refined, bleached, and deodorized (RBD) palm oil is severely concerning to the palm oil consumer. In the present study, the influence of the phosphoric acid degumming process on the formation of GE and 3-MCDE and in the RBD palm oil was determined with varying the acid dose (0.03-0.06 wt%), temperature (70-100 °C), and reaction time (15-45 min). The experimental conditions of the acid degumming process were designed following the central composite design of experiments, and they were optimized using Response Surface Methodology (RSM) based on the minimal formation of GE and 3-MCDE in the RBD palm oil. The optimal experimental conditions of the acid degumming process were a reaction time of 30 min, phosphoric acid concentration of 0.06 wt%, and temperature of 90 °C. Under these experimental conditions, the minimal GE and 3-MCDE formation in RBD palm oil were determined to be 0.61 mg/kg and 0.59 mg/kg; respectively. Several analytical methods were employed to determine RBD palm oil quality, including color, phosphorus, free fatty acids (FFAs), peroxide values, and fatty acid properties. It was found that the phosphoric acid degumming of CPO effectively removed the phosphorus and hydroperoxide content without conceding the quality of palm oil.

Recommendations for Oil Extraction and Refining Process to Prevent the Formation of Monochloropropane-diol Esters in Sunflower Oil

The aim of this study was to identify the chlorine source during sunflower oil production and propose mitigation strategies in order to prevent monochloropropane-diol ester (MCPDE) formation. Whole sunflower seeds, the separated kernel, hulls, and pressed cake were studied to pinpoint the location of chlorine donors originating from the crop. Acid-water-based degumming, bleaching, cooling, and heat treatment were performed to mimic the current refining process practices. Various oil extraction and refining scenarios were tested. MCPDE and total monochloropropane-diol (MCPD) content of the heat-treated samples were determined by liquid chromatography-HRMS and by an AOCS Official method. The results show that the oil produced from crop hulls and the bleaching clay used are the strongest chlorine sources boosting the MCPDE formation. Using a mixture of pressed and solvent extracted cake oil as model, total 3-MCPD decreased by a factor of 2 when applying static cooling in combination with a washed bleaching clay.